GREENSBORO, N.C. (AP) — North Carolina had little trouble advancing in the NCAA tournament — even with John Henson on the sideline wearing a suit. The Tar Heels may not have that luxury much longer.

Tyler Zeller had 17 points and 15 rebounds to help North Carolina beat Vermont 77-58 on Friday in its NCAA tournament opener despite playing without its shot-blocking and rebound-snatching starter.

Freshman forward James Michael McAdoo added a season-high 17 points for the top-seeded Tar Heels (30-5), who pushed ahead by double figures late in the first half and then broke the game open after halftime. The Tar Heels improved to 30-1 in NCAA tournament games played in their home state.

Sandro Carissimo had 11 points for the 16th-seeded Catamounts (24-12), who beat Lamar in one of Wednesday's First Four games. That earned them a trip to Greensboro to face the Tar Heels in front of a home-state crowd wearing plenty of light blue.

The Tar Heels didn't turn in a rousing performance, but they had a danger-free afternoon and advanced to play Creighton on Sunday in the third round of the Midwest Regional. They also bought Henson another two days to recover from that sprained left wrist.

The 6-foot-10 junior was hurt during last week's Atlantic Coast Conference tournament and missed the last two games in Atlanta. He had practiced this week and said he hoped to play Friday, but coach Roy Williams didn't sound sure Thursday that Henson would be ready and the team ruled him out about 90 minutes before tipoff.

With Henson out of uniform and McAdoo starting in his place for the third straight game, Williams can look forward to another round of questions about Henson's health before Sunday.

McAdoo shook off a bad shooting start and went 6 for 14 from the field to go with six rebounds. Zeller shot just 4 for 9 from the floor but went 9 of 10 at the free throw line and was a rebound shy of a double-double by halftime.

Harrison Barnes also finished with 14 points, while Kendall Marshall had 11 points and 10 assists for UNC. The Tar Heels shot just 42 percent, but scored 24 points off 20 turnovers.

North Carolina led by 12 at halftime, then blew the game open on consecutive three-point plays from McAdoo in the paint. Fellow freshman P.J. Hairston followed with a 3-pointer that pushed North Carolina's lead to 57-37 with about 8½ minutes left, sending the Tar Heels on to an easy finish.

The Catamounts shot 40 percent and missed 15 of 18 3-point tries. Perhaps no Vermont player struggled more than leading scorer Four McGlynn, who came in averaging about 12 points off the bench.

The freshman had 18 points against Lamar, but finished with just six against the Tar Heels on 2-for-13 shooting. He also missed all six of his shots from beyond the arc.